TSL2562, TSL2563

LOW-VOLTAGE

LIGHT-TO-DIGITAL CONVERTER

TAOS066J − MAY 2007

21

The LUMENOLOGY r Company

r

r

Copyright E 2007, TAOS Inc.

www.taosinc.com

APPLICATION INFORMATION: SOFTWARE

The following example pseudo code illustrates the configuration of an SMB Alert style interrupt when the light

intensity changes 20% from the current value, and persists for 3 conversion cycles:

// Read current light level

Address = 0x39

//Slave addr also 0x29 or 0x49

Command = 0xAC

//Set Command bit and Word bit

ReadWord (Address, Command, DataLow, DataHigh)

Channel0 = (256 * DataHigh) + DataLow

//Calculate upper and lower thresholds

T_Upper = Channel0 + (0.2 * Channel0)

T_Lower = Channel0 – (0.2 * Channel0)

//Write the lower threshold register

Command = 0xA2

//Addr lower threshold reg, set Word Bit

WriteWord (Address, Command, T_Lower.LoByte, T_Lower.HiByte)

//Write the upper threshold register

Command = 0xA4

//Addr upper threshold reg, set Word bit

WriteWord (Address, Command, T_Upper.LoByte, T_Upper.HiByte)

//Enable interrupt

Command = 0x86

//Address interrupt register

Data = 0x23

//SMBAlert style, PERSIST = 3

WriteByte(Address, Command, Data)

In order to generate an interrupt on demand during system test or debug, a test mode (INTR = 11) can be used.

The following example illustrates how to generate an interrupt on demand:

// Generate an interrupt

Address = 0x39

//Slave addr also 0x29 or 0x49

Command = 0x86

//Address Interrupt register

Data = 0x30

//Test interrupt

WriteByte(Address, Command, Data)

//Interrupt line should now be low